New Challenges in Terrestrial and Marine Radioecology

Ecosystem is a complex network of living organisms and their surrounding physical environment. The ecosystem is divided into various smaller compartments between which there is a continuous flow of energy. The intricate interactions and interlinking between them are the reason for the interdependence of the components on each other. The relationship between ecosystems and radioactivity has garnered significant attention due to the potential implications for both environmental health and human well-being with the expansion of nuclear-based sources of energy. Radioactivity, of natural origin, is distributed and in equilibrium in the various compartments of the ecosystem, but that arising from anthropogenic sources has the potential to disturb the delicate balance of ecosystems, affecting various organisms and disrupting ecological processes especially when present or introduced in large quantities. Radionuclides can enter ecosystems through various pathways, including air, water, and soil. Once introduced, they can undergo processes such as deposition, uptake, translocation, and bioaccumulation, depending on a range of factors such as their half-life, chemical properties, mobility, and ecological interactions leading to their transfer through the food chain. The consequences of such transfer are biomagnification, where radionuclides become increasingly concentrated at higher trophic levels and potentially impacting entire food webs. Radioecology encompasses all radiological interactions, affecting biological and geological material as well as those between different phases of matter, between which radionuclides migrate and get transferred. The response of the ecosystem to radioactivity is complex and multifaceted wherein some organisms may even exhibit tolerance or adaptive responses to radiation exposure, while others may suffer detrimental effects. This chapter aim to provide an overview of the key interactions between radioactivity and ecosystems, highlighting the different mechanisms through which radioactivity can enter and propagate within ecological systems, and some case studies of the subsequent adaptive ecological responses.